Final Fantasy I & II: Dawn of Souls - Mysidia Cave - Ghosts
Open the treasure chest containing a Drain Tome and a set of Ghosts will come by to ambush you. A quantity of one to 5 of these Ghosts will appear in battle. If a Ghost gets you with a physical attack, it will drain your health to add to its own. It also has spells such as tier 16 scourge and stun spells. It will also use the tier 7 mini ability to shrink your fighters, reducing their attack power when shrunk. Even if you battle these Ghosts at the maximum quantity, you may have a hard time succeeding, especially if your level and stats are high enough. These Ghosts are resistant to most spells, and the drain spell will restore their health. Their only weakness is the fire spell, so make sure the tier you cast for one is high enough to get rid of them in one variation. After the battle, continue exploring the cave.